Mechanism of peak drift of a grating monochromator and a designed sequential inductively coupled plasma spectrometer with an intelligent wavelength calibrating device

Abstract

The mechanism of the peak drift of exit spectral lines of a grating monochromator was studied experimentally and theoretically. The results indicate that the peak drift is due not only to temperature change, but also to wavelength change and systematic errors. Equations describing the non-linear functional relationship between peak drift, wavelength and temperature were obtained. Based on these equations, a computer wavelength-calibrating program was developed, and an intelligent wavelength-calibrating device was designed for use with a sequential ICP spectrometer instead of the conventional local thermostat or the real-time line-profile method. The sequential ICP spectrometer with the intelligent wavelength-calibrating device (designated the ICP-IWC) was used to analyse various standards. The analytical results were in good agreement with the certified values, and the RSDs of the determinations were about 1%. Compared with the use of the conventional local thermostat or the line-profile method, the ICP-IWC has been shown to be effective; the IWC device is easy to construct and should find wide application.